Ink jet textile printing of textile materials carried out using an ink jet printer is advantageous as compared with screen textile printing, roller textile printing and rotary textile printing in many aspects in that: a plate making step is not required thereby enabling simplification of steps; a digitalized design can be printed as it is via a computer; various types of products can be produced even in small quantities; the amount of waste liquids of color paste and the like can be significantly reduced; and the like. On the other hand, ink jet textile printing involves a problem of low print processing speed, and difficulty in expressing deep colors, and the like as compared with conventional plate-making textile printing. Therefore, ink jet textile printing has been predominantly used for producing sample textiles, and for small-scale production.
In recent years, ink jet textile printing has been increasingly popular as a result of significant improvement in printing speed of ink jet printers due to technical progress of image processing by means of a computer, and print head manufacturing, also with demands on market for digitalization of print designs, and on diversification and lot reduction in print processing.
As dye inks for ink jet textile printing, acidic dye inks for polyamide fibers such as silk and nylon; dispersion dye inks for polyester fibers; reactive dye inks for cellulosic fibers such as cotton and rayon; and the like have been commercially available. These dye inks for ink jet textile printing are generally aqueous inks prepared by dissolving or dispersing a dye in water. Furthermore, a compound, for example, a kind of glycol such as ethylene glycol, diethylene glycol, propylene glycol or triethylene glycol, or a monoalkyl ether of these glycols, or a solvent having a hydroxy group in the molecule such as glycerin, or the like is added to the ink for the purpose of suppressing drying of the ink owing to evaporation of the moisture, and adjusting the viscosity of the ink. However, the reactive dye fixes to the textile via a reaction of reactive groups that are present in the dye molecules with hydroxy groups that are present in the textile. Thus, when the aforementioned solvent or the like is added to an ink containing a reactive dye, hydroxy groups included in the solvent or the like react with the reactive dye during the storage of the ink, as well as in the reaction and fixation step carried out by heating for the purpose of fixing the dye after the textile printing, whereby a problem of lowered fixation ratio of the dye to the textile may occur. Therefore, the solvent or the like added into the reactive dye ink must be selected from among those that exhibit a low reactivity with the reactive dye, and thus such solvents and the like have been proposed. Specific examples of such a solvent which have been conventionally known include thiodiglycol (Patent Document 1), propylene glycol (Patent Document 2), 1,3-butanediol (Patent Document 3), EO adducts of glycerin (Patent Document 4), polypropylene glycol (Patent Document 5), and the like.
Patent Document 1: Japanese Unexamined Patent Application Publication No. H05-246132 (example 1)
Patent Document 2 Japanese Unexamined Patent Application Publication No. 2002-241639 (example 3)
Patent Document 3: Japanese Unexamined Patent Application Publication No. 2003-306627 (example 2)
Patent Document 4: Japanese Unexamined Patent Application Publication No. 2001-146561
Japanese Unexamined Patent Application (Translation of PCT Application), Publication No. 2005-520015